Scanning mirror based light projection systems are known in the field of illumination systems. WO2013/029667 and US2014/0029282 disclose examples of such systems, where the light source is a laser type light source. The advantage of using a laser light source is or example that laser-based illumination systems can generate very pure white light. A scanning mirror rotatable around two orthogonal axes is actuated and receives a light signal from a primary light source to project an image on to a phosphorous element. The light radiated by the primary light source, or more specifically its luminous intensity, for example, can be modulated to project a desired image on to the phosphorous element. The phosphorous element is then arranged to perform a wavelength conversion of the light signal received from the primary light source. Consequently the phosphorous element, acting as a secondary light source, re-emits light, which when combined with the light from the primary light source produce useful white light in different directions. In this kind of system a very high overall energy efficiency can be obtained as the wavelength conversion done by the phosphorous element is more energy efficient than the electrical-to-optical conversion done by the laser light source. Instead of using one scanning mirror rotatable around two orthogonal axes, it possible to use two mirrors instead, each movable around one axis, where the two axes are mutually orthogonal. This kind of lighting system can be used for example in vehicle headlights.
It is, however, difficult to efficiently control the above described illumination system to truly provide a smart illumination system, which could for instance, when applied to vehicle headlights, adapt the illumination to take into account current road conditions. For instance, the solution disclosed in US2014/0029282 does not provide sufficient control of the illumination system to be considered a truly smart illumination system. For instance, the illumination beam is not capable of moving horizontally or vertically. Furthermore, generally in headlights, three different light bulbs are needed: one for low beam, one for full beam and one for the indicator. Typically, each of these light bulbs is controlled by its own motor. However, this is not an optimal solution in terms of use of space and energy consumption. Moreover, the currently available image projection systems need at least one image frame or line buffer to temporarily store the images and possibly modify it before it is projected. Such a buffer is needed in the current solutions at least in the graphics processing unit (GPU) connected to a projector, but often also the projector comprises a similar buffer. Reading data from the buffer consumes energy and also means that the projected image cannot be modified in real-time.